Star feed for machine tools



May 18, 1943.

W. R. MILLER STAR FEED FOR MACHINE TOOLS Filed July 25, 1942 mum Patented May 18, 1943 UNITED STATES PATENT OFFICE I Q I 2,319,701 I h 7 I I O t STAR FEED FOR MACHINE TOOLS William R. Miller, Philadelphia, Pa, assignor to Wm. Sellers & Company, Inc., Philadelphia, Pa., a corporation of Pennsylvania Application July 25. 1942, Serial No. 452,365

(Cl. 82-1) I 6 Claims.

This invention relates to tool feeding devices for machine tools and, more particularly, to that type-of feed generally referred to as a star feed.

In the usual construction of such devices, it is necessary for the machine operator to make as many individual adjustments of the star feed control as are necessary to advancement of the star feed through a selected number of steps, and an important object of the present invention is the provision of an extremely simple apparatus readily adaptable to the ordinary machine tool construction, enabling a shift from one to another selected feed which requires only a single operation on the part of the machine operator.

A further object of the invention is the provision of an apparatus of this character which is extremely simple in its construction and operation, which is not subject to any considerable wear, and which may be-rnanuiactured at an extremely low cost. These and other objects I attain by the construction shown in the acconm'anyingv drawing,

wherein, for the purpose of illustratiom'l have shown a preferred embodiment of my invention and wherein: a

Fig. l is a fragmentary transverse sectional view through a feed mechanism constructed in accordance with my invention, the section being taken on line i-! of Figure 2;

' Fig. 2 is a sectional view taken'o'n line 2-2 of Fig. l;

Figure 3 is a detail sectional view showing the pin in its extendedposition and illustrating the passage of the pin from one to another of studs which are in contacting relation; and

Figure 4 is a similar section but illustrating the pin in its withdrawn position and as having its head arranged between spaced studs.

In illustrating my invention, I have shown the same as applied to an ordinary facing head H! which; is only fragmentarily illustrated. The facing head I!) is rotatable and has mounted thereon a shaft l l coacting in any usual manner with a tool slide carried by the head (not herein shown). This shaft has secured thereto a star wheel l2, the periphery of which is shown as projecting through a slot l3 in the head I!) and opening at that side of the head opposing a bearing element [4 in which facing head I is rotatably mounted.

The actuating mechanism for the star wheel comprises a pin plate l5 fixed in relation to the mounting l4 and a relatively adjustable cam plate 16, the adjusted position of which with relation to the pin plate may be determined by an indicator handle ll mounted in cam plate. and coacting with a selected one of a series of notches IS on the pin plate [5. The adjustment once secured may be determined by means of a clamping nut IS on a stud 20 carried by the pin plate l5 and projecting through an arcuate slot 2| in cam plate IS.

The pin plate l5 bears a concentric circular series of actuating pins for coaction with the teeth of star wheel I2, each pin upon engagement with the star wheel, actuating the star wheel through one step. As at present shown, these pins comprise a plurality of extensible pins 22 and a ingle stationary pin 23, the apparatus at present illustrated having no zero feed point, although this may, of course, be provided if de-' sired. Since, however, in ordinary feed mechanisms of this character means are provided for completely disconnecting the feed when unnecessary,the' present construction is preferred.

Each of the extensible pins 22 embodies a conically tipped head 24 the base of the head of which is engaged by a spring 25 acting normally to withdraw the stem' of the pin from engagement with the teeth .of the star wheel. The pin 23 and pins 24 are equidistantly spaced about the pin plate andthe cam plate 15 is equipped witha series of pain lobes for actuating the same. ,These can! lobes, which are presently shown as being in. the form of headed studs 25 mounted in the cam plate, are so disposed that with adjustment of the cam plate in various positions this series of the movable pins 22 will have their stemsprm ject for engagement with the teeth of the star wheel. With the grouping at present illustrated, it is possible to provide actuation of the star wheel through either 1, 2, 3, 4, 6 or 12 steps during each rotation of head II].

In the position in which the apparatus is at present illustrated, there are two active pins, these being the fixed pin 23 which is effective in all positions of the cam plate and the diametrically opposed extensible pin whose head is shown at 24. It will be noted that by a single counterclockwise step from the illustrated position, the extensible pin, which is at present active, will become inactive and that two other of the extensible pins will be rendered active, thus providing for three actuations of the star wheel at each revolution, whereas, upon a clockwise movement of the cam plate through a single step, the pin 23 will become the only pin which is active. Further adjustments will provide the remaining operations noted.

While it is obviously possible to form the cam lobes directly upon cam plate I 5 instead of utilizing the stud structure herein illustrated, the illustrated form is much more readily manufactured and is accordingly preferred. Since the structure is capable of considerable modification Without departing from the spirit of my invention, I do not wish to be understood as limiting myself to the particular arrangement herein shown except as hereinafter claimed.

I claim:

1. In a star feed of the type described, relatively rotatable structures, one including a feed shaft and a star Wheel actuator therefor, the other structure comprising a pin plate having a circular series of circumferentially spaced extensible pins for engagement with the teeth of the star wheel, spring means normally maintaining said pins in inoperative position, means for extending selected groups of said pins comprising a cam plate associated with said pin plate and having a circular series of lobes for coaction with said pins, and means torelatively adjust said pin and cam plates.

2. In a star feed of the type described, relatively rotatable structures, one including a feed shaft and a star wheel actuator therefor, the other structure comprising a pin plate having a circular series of circumferentially spaced pins for engagement with the teeth of the star wheel, said series including stationary and extensible pins, spring means normally maintaining said extensible pins in inoperative position, means for extending selected groups of said extensible pins comprising a cam plate associated with said pin plate and having a circular series of lobes for coaction with said pins, and means to relatively adjust said pin and cam plates.

3. In a star feed of the type described, relatively rotatable structures, one including a feed shaft and a star wheel actuator therefor, the

other structure comprising a pin plate having a circular series of uniformly circumferentially spaced pins for engagement with the teeth of the star wheel, said series including stationary and extensible pins, spring means normally maintaining said extensible pins in inoperative position, means for extending selected groups of said extensible pins comprising a cam plate associated with said pin plate and having a circular series of lobes for coaction with said pins, and means to relatively adjust said pin and cam plates, the lobes of said cam plate being so arranged that the extended pins of any groupand said stationary pin are equiangularly spaced in said series.

4. In a star feed of the type described, relatively rotatable structures, one including a feed shaft and a star Wheel actuator therefor, the other structure comprising a. pin plate having a. circular series of circumferentially spaced extensible pins for engagement with the teeth of the star wheel, said pins each having a conical head, spring extending between said plate and the heads of said pins and normally maintaining said pins in inoperative position, means for extending selected groups of said pins comprising a cam plate associated with said pin plate and having a circular series of studs for coaction with said pins, and means to relatively adjust said pin and cam plates.

5. In a star feed of the type described, relatively rotatable structures, one including a feed shaft and a star wheel actuator therefor, the other structure comprising a pin plate having a circular series of uniformly circumferentially spaced pins for engagement with the teeth of the star wheel, said series including stationary and extensible pins, said extensible pins each having a conical head, springs extending between said plate and the heads of said extensible pins and normally maintaining said extensible pins in inoperative position, means for extending selected groups of said extensible pins comprising a cam plate associated with said pin plate and having a circular series of lobes for coaction with said pins, and means to relatively adjust said pin and cam plates.

6. In a star feed of the type described, relatively rotatable structures, one including a feed shaft and a star wheel actuator therefor, the other structure comprising a pin plate having a circular series of uniformly circumferentially spaced pins for engagement with the teeth of the star wheel, springs extending between said plate and the heads of said extensible pins and normally maintaining said extensible pins in inoperative position, means for extending selected groups of said extensible pins comprising a cam plate associated with said pin plate and having a circular series of lobes for-coaction with said pins, and means to relatively adjust said pin and cam plates, the lobes of said cam plate being so arranged that the extended pins of any group and said stationary pin are equiangularly spaced in said series.

WILLIAM R. MILLER. 

